1. Field of the Invention
The present invention relates to a broadcasting receiver which receives the broadcasts of predetermined channels transmitted from broadcast stations, by a directivity switching antenna.
2. Description of the Related Art
In Japan, in general, the broadcast electric waves of television broadcasts or the likes are transmitted from a base station in one place. Therefore, substantially all of the broadcasts which a plurality of broadcast stations transmit can be received in such a way that an antenna for receiving the broadcasts is fixed to the roof, the veranda or the like of a house so as to look toward the base station, and that the antenna and a broadcasting receiver are connected by a cable. In contrast, in countries such as United States of America, broadcast electric waves are individually transmitted from a plurality of broadcast stations, respectively. Therefore, when an antenna is fixed looking toward one place, the broadcast of the broadcast station located in a direction in which the antenna looks can be received, but the broadcast of the broadcast station located in a direction in which the antenna does not look cannot be received.
In view of the above circumstances, therefore, broadcasting receivers each of which utilizes an antenna capable of switching the directivity thereof (hereinbelow, termed “directivity switching antenna”) have been proposed (refer to JP-A-2001-168627, JP-A-11-298226, and JP-A-6-334931). The directivity switching antenna includes a plurality of antenna elements, and phase shifters, etc. corresponding to the individual antenna elements. It controls the phases of signals received by the respective antenna elements, by the corresponding phase shifters, and then combines the resulting signals, thereby to electrically vary the directivity. Regarding a smart antenna which is one example of the directivity switching antenna, it is stipulated by standards to switch the directivity in the 16 directions of the surroundings. The broadcasting receiver controls such a directivity switching antenna and switches the direction of the directivity of the antenna to a predetermined direction, thereby to receive the broadcast electric wave of a predetermined channel transmitted from a predetermined broadcast station. Thus, even when a user has fixed the directivity switching antenna to the roof or the like of a house, the user can receive almost all the broadcasts transmitted from the plurality of dotted broadcast stations.
In a case where a desired channel is to be set as a reception channel in the broadcasting receiver as mentioned above, the user selects one desired channel by manipulating manipulation means such as a remote controller or switches, whereupon the user switches on the directions of the directionalities of the directivity switching antenna by manipulating the manipulating means. More specifically, the controller of the broadcasting receiver switches on the directions of the directionalities of the directivity switching antenna on the basis of the user's manipulation instructions. On this occasion, the controller processes broadcast electric waves received by the directivity switching antenna and displays pictures on, for example, a television receiving set (hereinbelow, abbreviated to “TV set”) in succession. Therefore, the user switches on the directions of the directionalities of the directivity switching antenna in such a way that, while watching the pictures displayed on the TV set, the user manipulates the manipulation means so as to obtain the best picture. Besides, when the direction of the directivity of the directivity switching antenna affording the best picture has been specified, the user sets the channel under reception and the specified direction of the directivity of the directivity switching antenna, in the broadcasting receiver by performing a predetermined manipulation through the manipulation means. Thus, the controller stores in a memory, channel information which indicates the selected channel, and direction information which indicates the direction of the directivity of the directivity switching antenna at this time.
The user can set a plurality of channels in the broadcasting receiver as reception channels by similarly performing the procedures as stated above, for the other channels. Besides, with such settings of the reception channels, when the user has thereafter selected any set channel again by manipulating the manipulation means, the controller reads out of the memory the direction information of the directivity switching antenna corresponding to the particular channel, and it switches the directivity of the directivity switching antenna to the direction indicated by the direction information. Accordingly, the broadcast of the selected channel can be immediately received by the directivity switching antenna, and the best image of the corresponding broadcast can be displayed on the TV set so as to be immediately viewed by the user.
The manual channel settings explained above are disclosed in JP-A-2001-168627, JP-A-11-298226, and JP-A-6-334931. With the manual channel settings, however, the user must switch on the directions of the directionalities of the directivity switching antenna by manipulating the manipulation means while watching the display pictures of the TV set, resulting in the problems that the manipulation becomes complicated, and that a long time is required. Especially, when the number of channels to be set is large, the manipulation becomes very complicated, and a very long time is required. Incidentally, it is stated in Patent Document 2 that, when a channel has been selected by way of example, the controller scans the directivity of the directivity switching antenna in all the directions so as to search for the direction of the level of the maximum reception power, and to hold the directivity of the directivity switching antenna in the direction searched for. However, this operation is performed for bringing the directivity of the directivity switching antenna into agreement with the direction in which the broadcast of the selected channel is receivable, and it is not performed for setting any desired channel. Besides, in a broadcasting receiver as disclosed in JP-A-8-242144 which utilizes an ordinary antenna not having its directivity switched, it is common practice that, when a power source has been turned ON or a predetermined manipulation has been done by way of example, a controller sequentially sweeps frequencies within a reception band so as to automatically store the reception frequencies of broadcast electric waves at and above a predetermined reception level or broadcast electric waves of high reception levels in the channel storing area of a memory.
Meanwhile, the directivity switching antenna fixed to the roof or the like of the house is sometimes moved on account of house-moving, cleaning or the like. When the directivity switching antenna has been moved, those directions of the directionalities of the directivity switching antenna in which the broadcasts of the set channels are receivable change in some cases, so that the broadcasts might fail to be received. Therefore, after the movement of the directivity switching antenna, channels need to be reset. However, in a case where the channel information items of the channels to be reset and the corresponding direction information items of the directivity switching antenna are stored in the memory in resetting the channels, such an inconvenience on a control occurs that, when the user has specified the channel to-be-reset, the controller controls the directivity switching antenna under the influence of the previous set contents so as to switch the directivity to the direction indicated by the corresponding direction information. It is accordingly apprehended that a long time will be expended in setting the channels to-be-reset and the directions of the directionalities of the directivity switching antenna. Incidentally, it is disclosed in JP-A-6-334931 that, when the broadcasting receiver with its directivity switching antenna fixed has been moved, the contents of the memory should preferably be reset so as to set the channels again. Nothing is explained, however, as to what kind of processing the resetting is and when and how the resetting is performed.